A few years ago, a locally famous blogger in San Francisco, known as Burrito Justice, created an exquisitely disorienting map, with help from a cartographer named Brian Stokle, and started selling copies of it online. The map imagined the city in the year 2072, after 60 years of rapid sea-level rise totaling 200 feet. At present, San Francisco is a roughly square-shaped, peninsular city. But on the map, it is severed clean from the mainland and shaved into a long, fat smudge. The shape of the land resembles a sea bird diving underwater for prey, with odd bays chewing into the coastlines and, farther out, a sprawl of bulging and wispy islands that used to be hills. If you lived in San Francisco, it was a map of where you already were and, simultaneously, where you worried you might be heading. “The San Francisco Archipelago,” Burrito Justice called it — a formerly coherent city in shards.

The map wasn’t science; it didn’t even pretend to be. I want to be very clear about that, because I worry it’s reckless to inject any more false facts into a conversation about climate change. Projecting the effect of sea-level rise on a specific location typically involves recondite computer models and calculations; Burrito Justice was just a fascinated hobbyist, futzing around on his laptop in his backyard. His entire premise was unscientific; for now, it is unthinkable that seas will rise so high so quickly. Even as most credible scientific estimates keep increasing and the poles melt faster than imagined, those estimates currently reach only between six and eight feet by the year 2100. That’s still potentially cataclysmic: Water would push into numerous cities, like Shanghai, London and New York, and displace hundreds of millions of people. And yes, there are some fringe, perfect-storm thought experiments out there that can get you close to 200 feet by the end of the century. But in truth, Burrito Justice settled on that number only because that’s how high he needed to jack up the world’s oceans if he wanted to wash out a particular road near his house. He has a friendly rivalry with another blogger, who lives in an adjacent neighborhood known for being a cloistered hamlet, and Burrito Justice thought it would be funny to see it literally become an island. So again: The map wasn’t science. It didn’t pretend to be. The point, initially, was just to needle this other guy named Todd.

Still, the San Francisco Archipelago has always stuck with me, because, almost in spite of itself, it managed to convey something peculiar and destabilizing about our climatological future. Burrito Justice hadn’t just redrawn the geography of a place; he’d also carried a sense of that place forward in time. And by transposing some of the grit and silly shibboleths of contemporary city life onto that alternate landscape, the map (and the little blog posts he wrote to accompany it) prodded you to entertain the possibility that this ruined future might not feel like an emergency to those living it, that life in that archipelago might have all the richness, realness and inanity of ours.